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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network76.2.64.0/19
Usable hosts8,190
Subnet mask255.255.224.0
Addresses8,192
Network address
76.2.64.0
Broadcast address
76.2.95.255
First usable
76.2.64.1
Last usable
76.2.95.254
Usable hosts
8,190 (8,192 less the network and broadcast addresses)
Subnet mask
255.255.224.0
Wildcard mask
0.0.31.255 (Cisco ACLs, OSPF)
Prefix length
/19
Type
Public public
Old class
A (default /8)
As numbers
Hex 4C024000 · Integer 1275215872 to 1275224063
Reverse DNS zones
64.2.76.in-addr.arpa
65.2.76.in-addr.arpa
66.2.76.in-addr.arpa
67.2.76.in-addr.arpa
68.2.76.in-addr.arpa
69.2.76.in-addr.arpa
70.2.76.in-addr.arpa
71.2.76.in-addr.arpa
72.2.76.in-addr.arpa
73.2.76.in-addr.arpa
74.2.76.in-addr.arpa
75.2.76.in-addr.arpa
76.2.76.in-addr.arpa
77.2.76.in-addr.arpa
78.2.76.in-addr.arpa
79.2.76.in-addr.arpa
and 16 more
/19 is not on a 8-bit boundary, so it takes 32 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001100.00000010.01000000.0000000076.2.64.0
Subnet mask11111111.11111111.11100000.00000000255.255.224.0
Network01001100.00000010.01000000.0000000076.2.64.0
Broadcast01001100.00000010.01011111.1111111176.2.95.255
Split into smaller subnets/30
/20 (2)/21 (4)/22 (8)/23 (16)/24 (32)/25 (64)/26 (128)/27 (256)/28 (512)/29 (1,024)/30 (2,048)/31 (4,096)

76.2.64.0/19 makes 2,048 subnets of /30; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.2.64.0/3076.2.64.1 to 76.2.64.276.2.64.32
276.2.64.4/3076.2.64.5 to 76.2.64.676.2.64.72
376.2.64.8/3076.2.64.9 to 76.2.64.1076.2.64.112
476.2.64.12/3076.2.64.13 to 76.2.64.1476.2.64.152
576.2.64.16/3076.2.64.17 to 76.2.64.1876.2.64.192
676.2.64.20/3076.2.64.21 to 76.2.64.2276.2.64.232
776.2.64.24/3076.2.64.25 to 76.2.64.2676.2.64.272
876.2.64.28/3076.2.64.29 to 76.2.64.3076.2.64.312
976.2.64.32/3076.2.64.33 to 76.2.64.3476.2.64.352
1076.2.64.36/3076.2.64.37 to 76.2.64.3876.2.64.392
1176.2.64.40/3076.2.64.41 to 76.2.64.4276.2.64.432
1276.2.64.44/3076.2.64.45 to 76.2.64.4676.2.64.472
1376.2.64.48/3076.2.64.49 to 76.2.64.5076.2.64.512
1476.2.64.52/3076.2.64.53 to 76.2.64.5476.2.64.552
1576.2.64.56/3076.2.64.57 to 76.2.64.5876.2.64.592
1676.2.64.60/3076.2.64.61 to 76.2.64.6276.2.64.632
1776.2.64.64/3076.2.64.65 to 76.2.64.6676.2.64.672
1876.2.64.68/3076.2.64.69 to 76.2.64.7076.2.64.712
1976.2.64.72/3076.2.64.73 to 76.2.64.7476.2.64.752
2076.2.64.76/3076.2.64.77 to 76.2.64.7876.2.64.792
2176.2.64.80/3076.2.64.81 to 76.2.64.8276.2.64.832
2276.2.64.84/3076.2.64.85 to 76.2.64.8676.2.64.872
2376.2.64.88/3076.2.64.89 to 76.2.64.9076.2.64.912
2476.2.64.92/3076.2.64.93 to 76.2.64.9476.2.64.952
2576.2.64.96/3076.2.64.97 to 76.2.64.9876.2.64.992
2676.2.64.100/3076.2.64.101 to 76.2.64.10276.2.64.1032
2776.2.64.104/3076.2.64.105 to 76.2.64.10676.2.64.1072
2876.2.64.108/3076.2.64.109 to 76.2.64.11076.2.64.1112
2976.2.64.112/3076.2.64.113 to 76.2.64.11476.2.64.1152
3076.2.64.116/3076.2.64.117 to 76.2.64.11876.2.64.1192
3176.2.64.120/3076.2.64.121 to 76.2.64.12276.2.64.1232
3276.2.64.124/3076.2.64.125 to 76.2.64.12676.2.64.1272
3376.2.64.128/3076.2.64.129 to 76.2.64.13076.2.64.1312
3476.2.64.132/3076.2.64.133 to 76.2.64.13476.2.64.1352
3576.2.64.136/3076.2.64.137 to 76.2.64.13876.2.64.1392
3676.2.64.140/3076.2.64.141 to 76.2.64.14276.2.64.1432
3776.2.64.144/3076.2.64.145 to 76.2.64.14676.2.64.1472
3876.2.64.148/3076.2.64.149 to 76.2.64.15076.2.64.1512
3976.2.64.152/3076.2.64.153 to 76.2.64.15476.2.64.1552
4076.2.64.156/3076.2.64.157 to 76.2.64.15876.2.64.1592
4176.2.64.160/3076.2.64.161 to 76.2.64.16276.2.64.1632
4276.2.64.164/3076.2.64.165 to 76.2.64.16676.2.64.1672
4376.2.64.168/3076.2.64.169 to 76.2.64.17076.2.64.1712
4476.2.64.172/3076.2.64.173 to 76.2.64.17476.2.64.1752
4576.2.64.176/3076.2.64.177 to 76.2.64.17876.2.64.1792
4676.2.64.180/3076.2.64.181 to 76.2.64.18276.2.64.1832
4776.2.64.184/3076.2.64.185 to 76.2.64.18676.2.64.1872
4876.2.64.188/3076.2.64.189 to 76.2.64.19076.2.64.1912
4976.2.64.192/3076.2.64.193 to 76.2.64.19476.2.64.1952
5076.2.64.196/3076.2.64.197 to 76.2.64.19876.2.64.1992
5176.2.64.200/3076.2.64.201 to 76.2.64.20276.2.64.2032
5276.2.64.204/3076.2.64.205 to 76.2.64.20676.2.64.2072
5376.2.64.208/3076.2.64.209 to 76.2.64.21076.2.64.2112
5476.2.64.212/3076.2.64.213 to 76.2.64.21476.2.64.2152
5576.2.64.216/3076.2.64.217 to 76.2.64.21876.2.64.2192
5676.2.64.220/3076.2.64.221 to 76.2.64.22276.2.64.2232
5776.2.64.224/3076.2.64.225 to 76.2.64.22676.2.64.2272
5876.2.64.228/3076.2.64.229 to 76.2.64.23076.2.64.2312
5976.2.64.232/3076.2.64.233 to 76.2.64.23476.2.64.2352
6076.2.64.236/3076.2.64.237 to 76.2.64.23876.2.64.2392
6176.2.64.240/3076.2.64.241 to 76.2.64.24276.2.64.2432
6276.2.64.244/3076.2.64.245 to 76.2.64.24676.2.64.2472
6376.2.64.248/3076.2.64.249 to 76.2.64.25076.2.64.2512
6476.2.64.252/3076.2.64.253 to 76.2.64.25476.2.64.2552
6576.2.65.0/3076.2.65.1 to 76.2.65.276.2.65.32
6676.2.65.4/3076.2.65.5 to 76.2.65.676.2.65.72
6776.2.65.8/3076.2.65.9 to 76.2.65.1076.2.65.112
6876.2.65.12/3076.2.65.13 to 76.2.65.1476.2.65.152
6976.2.65.16/3076.2.65.17 to 76.2.65.1876.2.65.192
7076.2.65.20/3076.2.65.21 to 76.2.65.2276.2.65.232
7176.2.65.24/3076.2.65.25 to 76.2.65.2676.2.65.272
7276.2.65.28/3076.2.65.29 to 76.2.65.3076.2.65.312
7376.2.65.32/3076.2.65.33 to 76.2.65.3476.2.65.352
7476.2.65.36/3076.2.65.37 to 76.2.65.3876.2.65.392
7576.2.65.40/3076.2.65.41 to 76.2.65.4276.2.65.432
7676.2.65.44/3076.2.65.45 to 76.2.65.4676.2.65.472
7776.2.65.48/3076.2.65.49 to 76.2.65.5076.2.65.512
7876.2.65.52/3076.2.65.53 to 76.2.65.5476.2.65.552
7976.2.65.56/3076.2.65.57 to 76.2.65.5876.2.65.592
8076.2.65.60/3076.2.65.61 to 76.2.65.6276.2.65.632
8176.2.65.64/3076.2.65.65 to 76.2.65.6676.2.65.672
8276.2.65.68/3076.2.65.69 to 76.2.65.7076.2.65.712
8376.2.65.72/3076.2.65.73 to 76.2.65.7476.2.65.752
8476.2.65.76/3076.2.65.77 to 76.2.65.7876.2.65.792
8576.2.65.80/3076.2.65.81 to 76.2.65.8276.2.65.832
8676.2.65.84/3076.2.65.85 to 76.2.65.8676.2.65.872
8776.2.65.88/3076.2.65.89 to 76.2.65.9076.2.65.912
8876.2.65.92/3076.2.65.93 to 76.2.65.9476.2.65.952
8976.2.65.96/3076.2.65.97 to 76.2.65.9876.2.65.992
9076.2.65.100/3076.2.65.101 to 76.2.65.10276.2.65.1032
9176.2.65.104/3076.2.65.105 to 76.2.65.10676.2.65.1072
9276.2.65.108/3076.2.65.109 to 76.2.65.11076.2.65.1112
9376.2.65.112/3076.2.65.113 to 76.2.65.11476.2.65.1152
9476.2.65.116/3076.2.65.117 to 76.2.65.11876.2.65.1192
9576.2.65.120/3076.2.65.121 to 76.2.65.12276.2.65.1232
9676.2.65.124/3076.2.65.125 to 76.2.65.12676.2.65.1272
9776.2.65.128/3076.2.65.129 to 76.2.65.13076.2.65.1312
9876.2.65.132/3076.2.65.133 to 76.2.65.13476.2.65.1352
9976.2.65.136/3076.2.65.137 to 76.2.65.13876.2.65.1392
10076.2.65.140/3076.2.65.141 to 76.2.65.14276.2.65.1432
10176.2.65.144/3076.2.65.145 to 76.2.65.14676.2.65.1472
10276.2.65.148/3076.2.65.149 to 76.2.65.15076.2.65.1512
10376.2.65.152/3076.2.65.153 to 76.2.65.15476.2.65.1552
10476.2.65.156/3076.2.65.157 to 76.2.65.15876.2.65.1592
10576.2.65.160/3076.2.65.161 to 76.2.65.16276.2.65.1632
10676.2.65.164/3076.2.65.165 to 76.2.65.16676.2.65.1672
10776.2.65.168/3076.2.65.169 to 76.2.65.17076.2.65.1712
10876.2.65.172/3076.2.65.173 to 76.2.65.17476.2.65.1752
10976.2.65.176/3076.2.65.177 to 76.2.65.17876.2.65.1792
11076.2.65.180/3076.2.65.181 to 76.2.65.18276.2.65.1832
11176.2.65.184/3076.2.65.185 to 76.2.65.18676.2.65.1872
11276.2.65.188/3076.2.65.189 to 76.2.65.19076.2.65.1912
11376.2.65.192/3076.2.65.193 to 76.2.65.19476.2.65.1952
11476.2.65.196/3076.2.65.197 to 76.2.65.19876.2.65.1992
11576.2.65.200/3076.2.65.201 to 76.2.65.20276.2.65.2032
11676.2.65.204/3076.2.65.205 to 76.2.65.20676.2.65.2072
11776.2.65.208/3076.2.65.209 to 76.2.65.21076.2.65.2112
11876.2.65.212/3076.2.65.213 to 76.2.65.21476.2.65.2152
11976.2.65.216/3076.2.65.217 to 76.2.65.21876.2.65.2192
12076.2.65.220/3076.2.65.221 to 76.2.65.22276.2.65.2232
12176.2.65.224/3076.2.65.225 to 76.2.65.22676.2.65.2272
12276.2.65.228/3076.2.65.229 to 76.2.65.23076.2.65.2312
12376.2.65.232/3076.2.65.233 to 76.2.65.23476.2.65.2352
12476.2.65.236/3076.2.65.237 to 76.2.65.23876.2.65.2392
12576.2.65.240/3076.2.65.241 to 76.2.65.24276.2.65.2432
12676.2.65.244/3076.2.65.245 to 76.2.65.24676.2.65.2472
12776.2.65.248/3076.2.65.249 to 76.2.65.25076.2.65.2512
12876.2.65.252/3076.2.65.253 to 76.2.65.25476.2.65.2552
12976.2.66.0/3076.2.66.1 to 76.2.66.276.2.66.32
13076.2.66.4/3076.2.66.5 to 76.2.66.676.2.66.72
13176.2.66.8/3076.2.66.9 to 76.2.66.1076.2.66.112
13276.2.66.12/3076.2.66.13 to 76.2.66.1476.2.66.152
13376.2.66.16/3076.2.66.17 to 76.2.66.1876.2.66.192
13476.2.66.20/3076.2.66.21 to 76.2.66.2276.2.66.232
13576.2.66.24/3076.2.66.25 to 76.2.66.2676.2.66.272
13676.2.66.28/3076.2.66.29 to 76.2.66.3076.2.66.312
13776.2.66.32/3076.2.66.33 to 76.2.66.3476.2.66.352
13876.2.66.36/3076.2.66.37 to 76.2.66.3876.2.66.392
13976.2.66.40/3076.2.66.41 to 76.2.66.4276.2.66.432
14076.2.66.44/3076.2.66.45 to 76.2.66.4676.2.66.472
14176.2.66.48/3076.2.66.49 to 76.2.66.5076.2.66.512
14276.2.66.52/3076.2.66.53 to 76.2.66.5476.2.66.552
14376.2.66.56/3076.2.66.57 to 76.2.66.5876.2.66.592
14476.2.66.60/3076.2.66.61 to 76.2.66.6276.2.66.632
14576.2.66.64/3076.2.66.65 to 76.2.66.6676.2.66.672
14676.2.66.68/3076.2.66.69 to 76.2.66.7076.2.66.712
14776.2.66.72/3076.2.66.73 to 76.2.66.7476.2.66.752
14876.2.66.76/3076.2.66.77 to 76.2.66.7876.2.66.792
14976.2.66.80/3076.2.66.81 to 76.2.66.8276.2.66.832
15076.2.66.84/3076.2.66.85 to 76.2.66.8676.2.66.872
15176.2.66.88/3076.2.66.89 to 76.2.66.9076.2.66.912
15276.2.66.92/3076.2.66.93 to 76.2.66.9476.2.66.952
15376.2.66.96/3076.2.66.97 to 76.2.66.9876.2.66.992
15476.2.66.100/3076.2.66.101 to 76.2.66.10276.2.66.1032
15576.2.66.104/3076.2.66.105 to 76.2.66.10676.2.66.1072
15676.2.66.108/3076.2.66.109 to 76.2.66.11076.2.66.1112
15776.2.66.112/3076.2.66.113 to 76.2.66.11476.2.66.1152
15876.2.66.116/3076.2.66.117 to 76.2.66.11876.2.66.1192
15976.2.66.120/3076.2.66.121 to 76.2.66.12276.2.66.1232
16076.2.66.124/3076.2.66.125 to 76.2.66.12676.2.66.1272
16176.2.66.128/3076.2.66.129 to 76.2.66.13076.2.66.1312
16276.2.66.132/3076.2.66.133 to 76.2.66.13476.2.66.1352
16376.2.66.136/3076.2.66.137 to 76.2.66.13876.2.66.1392
16476.2.66.140/3076.2.66.141 to 76.2.66.14276.2.66.1432
16576.2.66.144/3076.2.66.145 to 76.2.66.14676.2.66.1472
16676.2.66.148/3076.2.66.149 to 76.2.66.15076.2.66.1512
16776.2.66.152/3076.2.66.153 to 76.2.66.15476.2.66.1552
16876.2.66.156/3076.2.66.157 to 76.2.66.15876.2.66.1592
16976.2.66.160/3076.2.66.161 to 76.2.66.16276.2.66.1632
17076.2.66.164/3076.2.66.165 to 76.2.66.16676.2.66.1672
17176.2.66.168/3076.2.66.169 to 76.2.66.17076.2.66.1712
17276.2.66.172/3076.2.66.173 to 76.2.66.17476.2.66.1752
17376.2.66.176/3076.2.66.177 to 76.2.66.17876.2.66.1792
17476.2.66.180/3076.2.66.181 to 76.2.66.18276.2.66.1832
17576.2.66.184/3076.2.66.185 to 76.2.66.18676.2.66.1872
17676.2.66.188/3076.2.66.189 to 76.2.66.19076.2.66.1912
17776.2.66.192/3076.2.66.193 to 76.2.66.19476.2.66.1952
17876.2.66.196/3076.2.66.197 to 76.2.66.19876.2.66.1992
17976.2.66.200/3076.2.66.201 to 76.2.66.20276.2.66.2032
18076.2.66.204/3076.2.66.205 to 76.2.66.20676.2.66.2072
18176.2.66.208/3076.2.66.209 to 76.2.66.21076.2.66.2112
18276.2.66.212/3076.2.66.213 to 76.2.66.21476.2.66.2152
18376.2.66.216/3076.2.66.217 to 76.2.66.21876.2.66.2192
18476.2.66.220/3076.2.66.221 to 76.2.66.22276.2.66.2232
18576.2.66.224/3076.2.66.225 to 76.2.66.22676.2.66.2272
18676.2.66.228/3076.2.66.229 to 76.2.66.23076.2.66.2312
18776.2.66.232/3076.2.66.233 to 76.2.66.23476.2.66.2352
18876.2.66.236/3076.2.66.237 to 76.2.66.23876.2.66.2392
18976.2.66.240/3076.2.66.241 to 76.2.66.24276.2.66.2432
19076.2.66.244/3076.2.66.245 to 76.2.66.24676.2.66.2472
19176.2.66.248/3076.2.66.249 to 76.2.66.25076.2.66.2512
19276.2.66.252/3076.2.66.253 to 76.2.66.25476.2.66.2552
19376.2.67.0/3076.2.67.1 to 76.2.67.276.2.67.32
19476.2.67.4/3076.2.67.5 to 76.2.67.676.2.67.72
19576.2.67.8/3076.2.67.9 to 76.2.67.1076.2.67.112
19676.2.67.12/3076.2.67.13 to 76.2.67.1476.2.67.152
19776.2.67.16/3076.2.67.17 to 76.2.67.1876.2.67.192
19876.2.67.20/3076.2.67.21 to 76.2.67.2276.2.67.232
19976.2.67.24/3076.2.67.25 to 76.2.67.2676.2.67.272
20076.2.67.28/3076.2.67.29 to 76.2.67.3076.2.67.312
20176.2.67.32/3076.2.67.33 to 76.2.67.3476.2.67.352
20276.2.67.36/3076.2.67.37 to 76.2.67.3876.2.67.392
20376.2.67.40/3076.2.67.41 to 76.2.67.4276.2.67.432
20476.2.67.44/3076.2.67.45 to 76.2.67.4676.2.67.472
20576.2.67.48/3076.2.67.49 to 76.2.67.5076.2.67.512
20676.2.67.52/3076.2.67.53 to 76.2.67.5476.2.67.552
20776.2.67.56/3076.2.67.57 to 76.2.67.5876.2.67.592
20876.2.67.60/3076.2.67.61 to 76.2.67.6276.2.67.632
20976.2.67.64/3076.2.67.65 to 76.2.67.6676.2.67.672
21076.2.67.68/3076.2.67.69 to 76.2.67.7076.2.67.712
21176.2.67.72/3076.2.67.73 to 76.2.67.7476.2.67.752
21276.2.67.76/3076.2.67.77 to 76.2.67.7876.2.67.792
21376.2.67.80/3076.2.67.81 to 76.2.67.8276.2.67.832
21476.2.67.84/3076.2.67.85 to 76.2.67.8676.2.67.872
21576.2.67.88/3076.2.67.89 to 76.2.67.9076.2.67.912
21676.2.67.92/3076.2.67.93 to 76.2.67.9476.2.67.952
21776.2.67.96/3076.2.67.97 to 76.2.67.9876.2.67.992
21876.2.67.100/3076.2.67.101 to 76.2.67.10276.2.67.1032
21976.2.67.104/3076.2.67.105 to 76.2.67.10676.2.67.1072
22076.2.67.108/3076.2.67.109 to 76.2.67.11076.2.67.1112
22176.2.67.112/3076.2.67.113 to 76.2.67.11476.2.67.1152
22276.2.67.116/3076.2.67.117 to 76.2.67.11876.2.67.1192
22376.2.67.120/3076.2.67.121 to 76.2.67.12276.2.67.1232
22476.2.67.124/3076.2.67.125 to 76.2.67.12676.2.67.1272
22576.2.67.128/3076.2.67.129 to 76.2.67.13076.2.67.1312
22676.2.67.132/3076.2.67.133 to 76.2.67.13476.2.67.1352
22776.2.67.136/3076.2.67.137 to 76.2.67.13876.2.67.1392
22876.2.67.140/3076.2.67.141 to 76.2.67.14276.2.67.1432
22976.2.67.144/3076.2.67.145 to 76.2.67.14676.2.67.1472
23076.2.67.148/3076.2.67.149 to 76.2.67.15076.2.67.1512
23176.2.67.152/3076.2.67.153 to 76.2.67.15476.2.67.1552
23276.2.67.156/3076.2.67.157 to 76.2.67.15876.2.67.1592
23376.2.67.160/3076.2.67.161 to 76.2.67.16276.2.67.1632
23476.2.67.164/3076.2.67.165 to 76.2.67.16676.2.67.1672
23576.2.67.168/3076.2.67.169 to 76.2.67.17076.2.67.1712
23676.2.67.172/3076.2.67.173 to 76.2.67.17476.2.67.1752
23776.2.67.176/3076.2.67.177 to 76.2.67.17876.2.67.1792
23876.2.67.180/3076.2.67.181 to 76.2.67.18276.2.67.1832
23976.2.67.184/3076.2.67.185 to 76.2.67.18676.2.67.1872
24076.2.67.188/3076.2.67.189 to 76.2.67.19076.2.67.1912
24176.2.67.192/3076.2.67.193 to 76.2.67.19476.2.67.1952
24276.2.67.196/3076.2.67.197 to 76.2.67.19876.2.67.1992
24376.2.67.200/3076.2.67.201 to 76.2.67.20276.2.67.2032
24476.2.67.204/3076.2.67.205 to 76.2.67.20676.2.67.2072
24576.2.67.208/3076.2.67.209 to 76.2.67.21076.2.67.2112
24676.2.67.212/3076.2.67.213 to 76.2.67.21476.2.67.2152
24776.2.67.216/3076.2.67.217 to 76.2.67.21876.2.67.2192
24876.2.67.220/3076.2.67.221 to 76.2.67.22276.2.67.2232
24976.2.67.224/3076.2.67.225 to 76.2.67.22676.2.67.2272
25076.2.67.228/3076.2.67.229 to 76.2.67.23076.2.67.2312
25176.2.67.232/3076.2.67.233 to 76.2.67.23476.2.67.2352
25276.2.67.236/3076.2.67.237 to 76.2.67.23876.2.67.2392
25376.2.67.240/3076.2.67.241 to 76.2.67.24276.2.67.2432
25476.2.67.244/3076.2.67.245 to 76.2.67.24676.2.67.2472
25576.2.67.248/3076.2.67.249 to 76.2.67.25076.2.67.2512
25676.2.67.252/3076.2.67.253 to 76.2.67.25476.2.67.2552

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.